Various types of multiple component mixing and dispensing devices exist, including those in which the fluid chambers are in a side-by-side configuration, and those in which the fluid chambers are in a coaxial configuration. Such cartridges typically are placed in a hand-held applicator or gun having one or more movable plungers. The plungers move pistons associated with the fluid chambers to dispense and mix the two component fluids at a distal end of the cartridge.
A fluid cartridge of this general type includes respective first and second outlets at the distal end for discharging the two fluids from the fluid chambers into a mixing nozzle. The mixing nozzle includes an internal static mixing element that repeatedly combines layers of the two fluids for mixing purposes. The outlets of the cartridge are in fluid communication and are located adjacent to one another, such as in a coaxial or side-by-side arrangement within a proximal end of the mixing nozzle. Because these outlets are in direct fluid communication with one another when the static mixing nozzle is secured to the distal end of the cartridge, there is the potential for cross contamination of the two fluids within the nozzle at the location of the outlets. These fluids are often reactive with each other, such as in the case of an epoxy resin adhesive in which one of the fluids is a resin component and the other is a catalyst that will cause a chemical reaction and eventual hardening of the mixed fluids. This presents difficulties, such as when reusing the cartridge with the attached mixing nozzle, or when removing and later replacing the used mixing nozzle with a new nozzle. The residual fluids at the location of the cartridge outlets often contact each other, react, and harden to create a clogged condition.
It would therefore be desirable to provide a mixing nozzle for a fluid cartridge and a method that addresses these issues.